nixos/akkoma: Don't warn if no installWrapper

Currently the installWrapper warning is issued if sudo (and sudo-rs)
aren't installed.  This is fine, except we get the warning even if we
explicitly turn off installWrapper -- say, for this very reason!

Rather than warning on every build until either sudo is installed or
Akkoma is uninstalled, only warn if cfg.installWrapper is true.

nixos/modules/services/web-apps/akkoma.nix

@@ -957,7 +957,7 @@ in {
     assertions = optionals (cfg.config.":pleroma".":media_proxy".enabled && cfg.config.":pleroma".":media_proxy".base_url == null) [''
       `services.akkoma.config.":pleroma".":media_proxy".base_url` must be set when the media proxy is enabled.
     ''];
-    warnings = optionals (with config.security; (!sudo.enable) && (!sudo-rs.enable)) [''
+    warnings = optionals (with config.security; cfg.installWrapper && (!sudo.enable) && (!sudo-rs.enable)) [''
       The pleroma_ctl wrapper enabled by the installWrapper option relies on
       sudo, which appears to have been disabled through security.sudo.enable.
     ''];